Haul-off machines

ABSTRACT

A haul-off machine for hauling a continuously extruded article from an extruding machine and having a plurality of driven gripping means between and by which the extruded article can be hauled and the gripping means being movable towards and away from each other, to accommodate extruded articles of different crosssectional sizes, by pneumatic piston and cylinder devices of adjustment means which also includes a movement equalizing arrangement comprising hydraulic piston and cylinder devices to ensure that the driven gripping means on opposite sides of the extruded article move equal distances towards and away from each other.

I United States Patent 1 91 1111 3,744,695 Postins [4 July 10, 1973 1 HAUL-OFF MACHINES 3,620,432 11/1971 Emery 226/172 [75] lnventor: John George Postins, Wednesbury,

England Primary ExaminerRichard A. Schacher Attorney-George l-l. Spencer et al. [73] Ass1gnee: Mll Limited, Wolverhampton,

England [22] Filed: Jan. 17, 1972 [57] ABSTRACT A haul-off machine for hauling a continuously extruded [2| I Appl' 218,296 article from an extruding machine and having a plurality of driven gripping means between and by which the [30] F i A li ti priority D extruded article can be hauled and the gripping means Jan. 15 1971 Great Britain 2 020 71 being movable towards and away from each her, to

accommodate extruded articles of different cross- [52] [1.8. CI. 226/172 Sectional Sizes by pneumatic piston and cylinder 51 Int. Cl B65h 17/34 vices adjustment means which includes 8 P l [58] Field 61 Search 226/172 173 equalizing arrangement comprismg hydrauhc ton and cylinder devices to ensure that the driven gnp- [56] Reierences Cited ping meansl 051 opposite sidesj of this extruded articlfi move e ua istances towar s an away rom eac UNITED STATES PATENTS other q 3,022,928 2/1962 Ulmitz 226/172 3/1962 Gretter 226/172 2 Claims, 3 Drawing Figures PATENIEB JUL 1 0191s saw 2 OF 2 HAUL-OFF MINCHHNIES FIELD OF THE INVENTION This invention relates to haul-off machines of the kind comprising a supporting frame which supports one or more pairs of driven gripping means arranged to grip an article such as for example a plastics extrudate being delivered from an extruding machine so as to convey the extrudate from the extruding machine.

DESCRIPTION OF THE PRIOR ART It is known to provide a haul-off machine wherein the driven gripping means are urged towards each other to grip the article therebetween by fluid pressure piston and cylinder devices subjected to equal pressures but it is found that the subjection of the fluid pressure piston and cylinder devices to equal pressures on opposite sides of the article does not ensure that the gripping means on the opposite sides of the article will move equal distances towards and away from the article and to try to obtain equal movements of the gripping means on opposite sides of the article towards and away from said article, it is found that movement equalising means are essential. These movement equalising means have previously been of a mechanical nature involving mechanical linkages such as arms, chains, toothed sprockets links, levers and pivot pins and spindles and these mechanical means suffer the disadvantage that looseness or play develops due to wear and thus the accuracy of the equalising means is adversely affected.

Examples of the prior art are described in US. Pat. No. 3,620,432 and U.S. Pat. No. 3,022,928.

SUMMARY OF THE INVENTION According to the present invention there is provided a haul-off machine comprising:

a. a supporting frame,

b. one or more pairs of gripping means arranged to grip an article in an opening between said gripping means,

c. driving means to drive the gripping means to advance the article through the opening between said gripping means,

d. fluid pressure operated piston and cylinder gripping pressure means associated with the gripping means to move the gripping means of the or each pair of gripping means in directions towards and away from each other transverse to a longitudinal axis of said opening and dependent upon the cross sectional size of an article to be gripped and ad vanced,

e. one or more pairs of hydraulic piston and cylinder movement equalising devices respectively with regard to the one or more pairs of gripping means and said one or more pairs of hydraulic piston and cylinder movement equalising devices being disposed with their axes parallel with said directions of movement of the respective gripping means towards and away from each other, the gripping means of one pair thereof being connected to the piston members or to the cylinder members of the respective movement equalising devices whilst the other of said members are stationarily supported by said frame,

g. both ends of each cylinder member on opposite sides of a piston member being filled with liquid and h. an inner end of one cylinder member of a pair communicates with an outer end ofthe other cylinder member of said pair and of which other cylinder member the inner end thereof communicates with the outer end of said one cylinder member so that liquid displaced from an outer or inner end of said one cylinder member of said pair is transferred to the inner or outer end of said other cylinder member respectively and vice versa to constrain the two gripping means of a pair of gripping means to move equal distances towards and away from the longitudinal axis when said gripping means are moved by the fluid pressure operated gripping pressure means towards and away from said longitudinal axis and thus towards and away from an ar ticle between the gripping means.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be more particularly described by way of example with reference to the accompanying drawings in which:

FIG. 1 is a diagrammatic perspective view of the haul-off machine,

FIG. 2 is a front elevation of the machine, and,

FIG. 3 is a sectional plan view of FIG. 2 on the lines 22 thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT The haul-off machine is particularly suitable for hauling a plastics tubular extrudate article 10 which may be circular, from an extruding machine, the extrudate advancing horizontally in the direction of the arrow 12 and disposed about a longitudinal horizontal central axis X-Y. It 'should be appreciated, however, that the extrudate may be of any other required cross-sectional shape which may be regular or irregular.

The machine comprises a stationary supporting frame 14 including a base 16 to which are secured four vertical corner posts 18 connected together by upper and lower horizontal end bars 20 and 22 respectively. The frame 14 also comprises a vertical sub-frame 24 at each side of the frame and each sub-frame includes two uprights 26 secured at their lower ends to the base 16 and connected together by upper and lower cross-bars 28 and 30 respectively. Upper and lower horizontal side bars 32 and 34 connect the corner posts 18 to the sub-frame 24. e

To grip and advance the extrudate 10 there are provided four elongate gripping means defining an opening 35 therebetween, there being a pair of vertically movable gripping means 36 and 38 and a pair of horizontally moving gripping means are disposed longitudinally of and spaced equi-distantly from the central longitudinal axis X-Y. Each gripping means comprises an endless conveyor belt 44 mounted at its ends on rollers 46 and 48 of which the roller 46 is driven through suitable drive mechanism including worm and worm wheels, spur gears, shafts and universal joints and generally indicated at 50 from an electric motor 51 via a gearbox 53 and it should be appreciated that all four endless conveyors 44 are driven in synchronism so that the inner opposed runs of the conveyors grip the extrudate l0 and advance at the same speed as the extrudate in the direction of the arrow 12.

The rollers 46 and 48 are mounted on a carriage comprising two parallel spaced apart plates 52 and 54 of which the latter extends longitudinally beyond the former as shown in FIGS. 1 and 2 and the carriage is pivotally mounted on a transverse pivot pin 56 which passes through both plates and is secured to the inner end of a link 58 to enable the gripping means to rock towards and away from the longitudinal axis X-Y.

The outer end of each of the links 58 associated with the vertically movable gripping means is secured to a horizontal but vertically movable transverse rod 60, the opposite ends of which are each mounted in a slide block 62 and each upper slide block 62 is slidably mounted on a vertical guide bar 64 secured at its upper and lower ends in the upper and lower bars 28 and 30. The lower slide block 62 is slidably mounted on the lower end of the guide bar 64 and has secured thereto a guide sleeve 68 which is also mounted on the guide bar 64 and the lower link 58 carries the lower pivot pin 56 on which is mounted the lower gripping means 38 including the lower endless conveyor 44.

In order to move the upper and lower gripping means 36 and 38 and thus the upper and lower endless conveyors 44 vertically there is provided on each side of the machine a pneumatically operated piston and cylinder gripping device 70 of which the lower end of the cylinder 72 is secured to the lower slide block 62 and the upper end of the cylinder is supported by a bracket 71 also secured to the upper end of the guide sleeve 68 and the piston rod 74 is secured to the upper slide block 62 so that extension and contraction of the device 70 causes vertical movement of the upper and lower gripping means under the guidance of guide means comprising a pair of guide rods 64 and a pair of guide sleeves 68 and said guide means the device 70 form part of an adjustment means which also includes a movement equalising arrangement whereby the upper and lower gripping means 36 and 38 move equal distances towards and away from the axis X-Y so as to be at all times equispaced therefrom after said gripping means have been initially set equidistantly from said axis X-Y.

The movement equalising arrangement is a hydraulic arrangement and in-respect of the upper and lower gripping means is as follows. Adjacent the ends of the machine and mid-way between the sides thereof there are disposed four hydraulic piston and cylinder devices, there being a pair adjacent each end of the machine and each pair comprises an upper device 76 and a lower device 78 and two devices are disposed vertically and coaxially as shown in FIGS. 1 and 2 and the cylinder 75 of the upper device 76 is pivotally mounted at 80 to the stationary frame and the cylinder 77 of the lower device is pivoted at 82 to the stationary frame. Each hydraulic device 76 and 78 is of the kind known as a double-rod end device which includes a piston from opposite ends of which extend a piston rod through the ends of the cylinder so that the crosssectional areas of the two ends of the cylinder are equal.

The piston rod 84 of the device 76 is connected to the plate 54 of the upper carriage and the piston rod 86 of the device 78 is connected to the plate 54 of the lower carriage and the inner end of the cylinder of the upper device 76 is connected by a pipe 88 to the outer end of the cylinder of the lower device 78 and the outer end of the cylinder of the upper device 76 is connected by a pipe 90 to the inner end of the cylinder of the lower device 78. The two devices and the pipes conmeans are initially set so as to be spaced equidistantly.

from the longitudinal axis X-Y and thereafter when the pneumatic device is operated to adjust the upper and lower gripping means towards or away from each other the hydraulic movement equalising arrangement comprising the devices 76 and 78 ensure that equal. movements of the gripping means are effected. These equal movements follow in consequence of the equal cross-sectional areas of the devices 76 and 78 on opposite sides of the pistons thereof whereby equal volumes of liquid are transferred from one device to the other devices and as these devices are identical the upper and lower gripping means are constrained to move equal distances.

In addition to the adjustment means for the upper and lower vertically movable gripping means, adjustment means are also provided for the horizontally movable gripping means 40 and 42 and the adjustment means for the horizontally movable gripping means are similar to the adjustment means for the vertical gripping means 36 and 38 with only the differences that are rendered necessary due to the different disposition of the horizontally and vertically adjustable gripping means. Thus, upper and lower stationary horizontal transverse guide bars 92 and 94 are mounted in the cross-bars 28 and 30 and mounted on these guide bars are slide units 66 and 67 respectively to which are connected pneumatic devices 96 and 98 respectively and the units 66 and 62 support vertical but horizontally movable transverse rods 100 to which are connected, as previously described, the links 58 on the inner ends of which are mounted pivot pins 56 on which are pivotally mounted the two horizontally movable gripping means 40 and 42.

Movement equalising arrangements are associated with the gripping means 40 and 42 and these arrangements are identical with the arrangements described with reference to the vertically movable gripping means 36 and 38 respectively and comprise hydraulic piston and cylinder devices 102 and 104 and each pair of devices 102 and 104 at each end of the machine are connected by pipes 106 and 108 to provide closed hydraulic circuits and to operate in an equalising manner as previously described with reference to the devices 76 and 78.

The four pneumatic devices 70, 96 and 98 may all be connected through a single control valve to a common source of supply (not shown) so that all devices are operated simultaneously or alternatively the two pairs of devices 70, and 96 and 98, may be connected to separate control valves so that the vertically adjustable gripping means may be operated independently of the horizontally adjustable gripping means. Each pair 76 and 78, and 102 and 104, of the four pairs of hydraulic devices afford a virtually closed hydraulic circuit but the four circuits may be connected to a common liquid supply reservoir (not shown) for topping-up purposes but the connections would be such as to prevent escape of liquid from a circuit to the reservoir during normal adjustment of the gripping means.

It should be appreciated that as the movement equalising arrangement comprising the devices 76, 78, 102 and 104 of the adjustment means is a hydraulic arrangement and does not involve mechanical equalising arrangement looseness or play does not develop even over extended use so that the accuracy of the adjusting means is not adversely affected.

I claim:

1. A haul-off machine comprising:

a. a supporting frame (14),

b. one or more pairs of gripping means (36,38 or 40,42) arranged to grip an article in an opening between said gripping means,

c. driving means (51) to drive the gripping means to advance the article through the opening between said gripping means,

d. fluid pressure operated piston and cylinder gripping pressure means (70,70 or 96,98) associated with the gripping means (36,38 or 40,42) to move the gripping means of the or each pair of gripping means in directions towards and away from each other transverse to a longitudinal axis X-Y of said opening and dependent upon the cross-sectional size of an article to be gripped and advanced,

e. one or more pairs of hydraulic piston and cylinder movement equalising devices (76, 78 or 102, 104) respectively with regard to the one or more pairs of r gripping means (36, 38 or 40, 42) and said one or more pairs of hydraulic piston and cylinder movement equalising devices being disposed with their axes parallel with said directions of movement of the respective gripping means towards and away from each other,

f. the gripping means of one pair thereof being connected to the piston members (84,86) or to the cylinder members (75,77) of the respective movement equalising devices (76,78 or 102,104) whilst the other of said members are stationarily supported by said frame,

g. both ends of each cylinder member (75,77) on opposite sides of a piston member (84, 86) being filled with liquid and h. an inner end of one cylinder member ofa pair communicates (88) with an outer end of the other cylinder member (77) of said pair and of which other cylinder member (77 the inner end thereof communicates (90) with the outer end of said one cylinder member (75) so that liquid displaced from 2. A haul-off machine according to claim 1 comprisa. one or more pairs of elongate gripping means (36,38 or 40,42) disposed longitudinally of the longitudinal axis XY,

b. the or each elongate gripping means including carriage (52,54) pivotally mounted (56) between its ends about an axis transverse to the longitudinal axis X-Y to enable the elongate gripping means to rock towards and away from said longitudinal axis,

. the fluidpressure operated piston and cylinder gripping pressure means (70,70 or 96,98) being connected to the carriages (52,54) at the pivot mountings (56) to move the gripping means (46,38 or 40,42) towards and away from each other and the longitudinal axis X-Y and i one or more pairs of the hydraulic piston and cylinder movement equalising devices (76,78 or 102,104) disposed and operative at each end of the opposite ends of the one or more pairs of elongate gripping means (36,38 or 40,42). 

1. A haul-off machine comprising: a. a supporting frame (14), b. one or more pairs of gripping means (36,38 or 40,42) arranged to grip an article in an opening between said gripping means, c. driving means (51) to drive the gripping means to advance the article through the opening between said gripping means, d. fluid pressure operated piston and cylinder gripping pressure means (70,70 or 96,98) associated with the gripping means (36,38 or 40,42) to move the gripping means of the or each pair of gripping means in directions towards and away from each other transverse to a longitudinal axis X-Y of said opening and dependent upon the cross-sectional size of an article to be gripped and advanced, e. one or more pairs of hydraulic piston and cylinder movement equalising devices (76, 78 or 102, 104) respectively with regard to the one or more pairs of gripping means (36, 38 or 40, 42) and said one or more pairs of hydraulic piston and cylinder movement equalising devices being disposed with their axes parallel with said directions of movement of the respective gripping means towards and away from each other, f. the gripping means of one pair thereof being connected to the piston members (84,86) or to the cylinder members (75,77) of the respective movement equalising devices (76,78 or 102,104) whilst the other of said members are stationarily supported by said frame, g. both ends of each cylinder member (75,77) on opposite sides of a piston member (84, 86) being filled with liquid and h. an inner end of one cylinder member (75) of a pair communicates (88) with an outer end of the other cylinder member (77) of said pair And of which other cylinder member (77) the inner end thereof communicates (90) with the outer end of said one cylinder member (75) so that liquid displaced from an outer or inner end of said one cylinder member (75) of said pair is transferred to the inner or outer end of said other cylinder member (77) respectively and vice versa to constrain the two gripping means of a pair of gripping means to move equal distances towards and away from the longitudinal axis X-Y when said gripping means are moved by the fluid pressure operated gripping pressure means (70,70 or 96,98) towards and away from said longitudinal axis and thus towards and away from an article between the gripping means.
 2. A haul-off machine according to claim 1 comprising a. one or more pairs of elongate gripping means (36,38 or 40,42) disposed longitudinally of the longitudinal axis X-Y, b. the or each elongate gripping means including a carriage (52, 54) pivotally mounted (56) between its ends about an axis transverse to the longitudinal axis X-Y to enable the elongate gripping means to rock towards and away from said longitudinal axis, c. the fluid pressure operated piston and cylinder gripping pressure means (70,70 or 96,98) being connected to the carriages (52,54) at the pivot mountings (56) to move the gripping means (46,38 or 40,42) towards and away from each other and the longitudinal axis X-Y and d. one or more pairs of the hydraulic piston and cylinder movement equalising devices (76,78 or 102,104) disposed and operative at each end of the opposite ends of the one or more pairs of elongate gripping means (36,38 or 40,42). 